Well tool with load-free pivot connections



Feb. 25, 1969 H. L.. MGGILL WELL TOOL WITH LOAD-FREE PIVOT CONNECTIONS Sheet of E;

Filed June 18. 1965 R @uw M www o V ).7 NCMKT ,MA lQ .u Mm /QA H4 av. WB 0 H Feb. 25, 1969 H. L.. MGGILI. l 3,429,595

WELL TOOL WITH LOAD-FREE PIVOT CONNECTIONS Filed June 18. 1965 Sheet 2 of INVENTOR.

Hon/ara l. /I//cG/ BY #AeA/r, ARK/N wo EDLocK ATTORNEVJ' United States Patent O 3,429,595 WELL TOOL WITH LOAD-FREE PIVOT CONNECTIONS Howard L. McGill, Houston, Tex., assignor to Schlumy berger Technology Corporation, Houston, Tex., a corporation of Texas Filed June 18, 1965, Ser. No. 464,938 U.S. Cl. 285-320 Int. Cl. F161 39/00, 37/18, 25/00 5 Claims ABSTRACT 0F THE DISCLOSURE This invention relates to well tools of the type which are movable between surface and subsurface locations through a -well bore for conducting Well testing or completion operations. The invention is particularly concerned with providing improved means for releasably securing such tools at a subsurface location during certain operations.

In carrying out well testing and well completion operations such as `well testing under flowing and static conditions, squeeze cementing, acidizing or uid fracturing, it is customary to employ a number of different full-bore tools dependently suspended from a tubing string employed to transport the tools to and from the subsurface locations at which they are to be operated. Typically, the tool string for such operations may comprise a full-bore packer for isolating the well bore below the packer from the well control iiuid (e.g., drilling mud), a hold-down device to insure against inadvertent release of the packer, a uid by-pass to facilitate down-hole movement of the tool string through the mud column, and a test tool for controlling fluid communication between the isolated portion of the well bore and the tubing string. Instruments are usually included with the test tool for sensing and recording significant formation conditions.

When such an arrangement is used, a cooperatively arranged system of J-slots and pins between relatively movable members of the various tools is ordinarily ernployed to enable motion of the tubing string to selectively set the packer, close the by-pass and subsequently operate the testing tool. The hold-down, of course, operates in response to fluid pressures below the packer and within the tubing string in excess of hydrostatic head immediately above the packer when it has been set.

Typically, the test tool in such a string is usually comprised of a ltubular mandrel telescopically disposed within a tubular housing Iand a central valve assembly mounted in the mandrel bore. The upper end of the mandrel is connected to the lower end of the tubing string and the lower end of the housing is connected by the by-pass to the packer. Thus, when the packer is set and the by-pass is closed, the test tool housing is held in iiXed position to permit the mandrel to be moved relative thereto, by manipulating the tubing string, for operating the central valve assembly.

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The central valve assembly, from which instruments such as pressure gauges are customarily suspended, may be releasably secured within the mandrel in such a manner that while the test tool is within a Well, the valve assembly and suspended pressure gauges may be released therefrom and returned to the surface through the tubing string. Thus, by rwithdrawing the central valve assembly, a continuous full-opening passage is lprovided by passing tools and fluids through the tubing string to that portion of the 'well bore below the packer to conduct various well-completion operations immediately thereafter. The central valve assembly and suspended instruments may also be subsequently returned through the tubing string and related into position within the mandrel for conducting further tests.

To provide for releasable engagement of the central valve assembly in the test tool mandrel, it has been customary to provide one of these elements with movable latch members which are biased to automatically move into engagement |with the other element when the central valve assembly is positioned within the mandrel. To yachieve withdrawal of these latch members fro-m their accommodating recesses, releasing means are ordinarily provided that are selectively operable in some manner from the surface.

The central valve assembly may be conveniently retrieved from the test tool mandrel (once disengaged therefrom) in lany of several ways. JIf outfitted with a swab cup, the central valve assembly may be hydraulically retrieved by circulating the drilling fluid down the annulus and up the tubing from beneath the valve assembly (i.e., reverse circulation) Retrieval may also be accomplished by lowering suitable wire-line operated grappling means through the tubing string to engage a fishing neck associated :with the central valve assembly.

It will be recognized that any forces applied on the central valve assembly will also be imposed on the latch members. For example, a pressure differential across the central valve assembly, such as when measuring shutin pressures, will impose a substantial upwardly directed force on the latch members and their supports. Similarly, any downwardly directed force on the central valve assembly will be transmitted through the latch members and their supports to the tool mandrel.

It is not uncommon, therefore, for such forces to break or deform the latch members or their support members. When this occurs it may be thereafter impossible to release the latch members from engaged position and withdrawal of the tool string may be required to remove the central valve assembly from the tool mandrel. Moreover, even if retrieval is possible, after such a deformation or breaking, repair must be made before risking further use of the test tool. As those skilled in the art l'well known, the loss of rig time and the inconvenience which attend such damage present a significant problem 'in the conduct of testing and completion operations.

It is, therefore, an object of the present invent-ion to provide improved means by which one swell tool member, such as the above described central valve assembly, movable between surface and subsurface locations through a well bore, m-ay be releasably looked to another lwell tool member at a subsurface location in such a manner as to avoid deformation or fail-ure of the latching means.

This and other objects are obtained by providing such tools with releasable latching means capable of withstanding forces imposed during manipulation and operation of such tools and by arranging such latch means and latch support means in a cooperative manner -which avoids transmission of these forces through the latch support means once the latch means has been engaged.

Further understanding of the present invention by those skilled in the art may be had by reference to the following detailed description of the embodiment thereof which is illustrated in t-he appended drawings.

'In the drawings:

FIGURE 1 is -a somewhat simplified elevational view, partly in section, showing a typical string of tools within a Well bore.

FIGURE 2 is an enlarged elevational view, partly in section, detailing one embodiment of latch means arranged in accordance with the present invention in one of the tools shown in FIGURE 1.

FIGURE 3 is a view similar to FIGURE 2 but showing the latch means in withdrawn position.

FIGURE 4 is an isometric view of an embodiment of the latch members shown in FIGURES 2 and 3.

FIGURE 5 is an enlarged partial elevational view similar to, but rotated ninety degrees from FIGURE 3, and showing the latch means in extended position.

In the illustrated embodiment, and with particular reference to FIGURE 1, a string of tools (simply illustrated to facilitate understanding) is shown positioned in a well bore 11. The lowermost tool in the string is a fullbore packer 12 set within casing 13 by means of conventional slip .and drag-block assembly 14, which cooperates with mandrel 15 and mandrel abutment 16 to expand a resilient element 17 into sealing engagement with casing 13. When packer 12 is thus set, the lower portion 18 of well bore 11 is sealed off from the upper portion 19 of well bore 11 thereby isolating the formation 20 to be tested from the column of well control fluid or mud cont-ained in upper portion 19.

The packer 12 is conventionally arranged for compression setting, as indicated by the configuration of slips 14, and is coupled to a conventional pressure-responsive holddown 22 above the packer. In the event that the pressure below packer 12 should exceed the hydrostatic pressure of the mud column above packer 12, piston-like gripping members 23 of hold-down 22 will extend into setting engagement with casing 13. In this way there is :assurance that packer 12 will not be unseated when the pressure in portion 18 of well bore 11 is increased above the hydrostatic pressure of the mud column in portion 19 as,for example, during cementing or fracturing operations. To facilitate lowering tool string 10 in well bore 11 through, and :against the resistance of, well control uid contained within casing 13, a conventional by-pass 24 is carried above hold-down 22.

The test tool 21 is comprised basically of a tubular mandrel 26, test tool housing 25 which telescopically receiVes mandrel 26, and a central valve assembly 27 which is releasably locked Within the lower portion of mandrel 26 by a latching mechanism 28. The upper end of mandrel 26 is coupled to the lower end of a tubing string 9 and the lower end of the tool housing 25 is connected to by-pass 24. Thus, when packer 12 has been set and by-pass 2.4 closed, the test tool housing 25 which s secured to these tools 12 and 24 is heldin xed position and mandrel 26 may be moved relative thereto by manipulating the tubing string 9 to which mandrel 26 is coupled.

The central valve assembly 27 is releasably secured within the bore of mandrel 26 in such a manner that a1- though the test tool 21 is within the well bore 11, the central valve assembly 27 may be released therefrom and transported to the surface through the tubing string 9. With the central valve assembly 27 removed, a continuous full-opening passage is provided from the surface t0 that portion 18 of the well bore 11 which is beneath the full-bore packer 12V for conducting various well completion operations such as perforating, cementing or fracturing. The central valve assembly 27 and pressure gauges 29, which are conveniently suspended therefrom, may also be returned through the tubing string 9 and relatched in operating position in mandrel 26. When central valve assembly 27 and gauges 29 are thus returned to their latched position within mandrel 26, test tool 21 is :again capable of performing all of its testing functions.

The mandrel 26 is movably supported within housing 25 by means of inwardly projecting lugs (not shown) carried by housing 25 which are received in cooperatively arranged slots (not shown) in the mandrel 26. Since such lug .and slot arrangements are Well known to those skilled in the art and do not form a part of the present invention they have not been illustrated in the appended drawings. However, in the illustrated embodiment, the lug and slot system utilized permits mandrel 26 to be selectively moved into any one of three longitudinally spaced positions, relative to housing 25, by appropriate manipulation of the tubing string 9 to which mandrel 26 is coupled. Thus, when the central Valve assembly 27 is latched in operating position within mandrel 26, test tool 21 is positionable in any one of three operating positions:

(1) A normally closed or shut-in position in which fluid communication through the tool is blocked by positioning mandrel 26 in an intermediate position relative to housing 25 thereby closing oif flow through lateral ports 76 and 77.

(2) A reversing position in which fluid communication is established between the tubing string and upper portion 19 of well bore 11, above packer 12 by elevating mandrel 26 until lateral ports 78, 79 [and 80 -are aligned for uid communication.

(3) An open or^testing position (as shown in FIG- URE 1) wherein uid communication is established from lower portion 18 of well bore 11 beneath full-bore packer 12 through lateral ports 76 and 77 and into the tubing string by lowering the mandrel 26 relative to the housing Turning now to FIGURES 2 and 3, it will be Seen that the central valve assembly 27 is comprised of a tubular member 30 which may, as those skilled in the art well know, be made up of several threadedly coupled members to facilitate manufacture and assembly. A tubular sleeve 34, which may also be conveniently provided by threadedly coupled parts, is rotatively disposed around the upper end portion of tubular member 30 with its lower end resting on a bearing 38. Tubular sleeve 34 is free to rotate relative to central tubular member 30 but is prevented from moving longitudinally relative thereto by an inwardly directed annular shoulder 39 at its lower end that is confined, with bearing 38, between outwardly directed annular shoulders 40 and 41 on tubular member 30. At its upper end, sleeve 34 rotatively engages a coupling member 42, at opposed bearing surfaces and 46. A fishing neck and swab cup (not shown) may be connected to lmember 42 to facilitate transport of central valve assembly 27 through the tubing string 9 to the surface, as above described.

Longitudinal slots 47 are provided on opposite sides of the upper end of tubular sleeve 34 for receiving pivotally mounted latch members 48. To provide for pivotal extension of latch members 48, slots 47 have a radial projection 50 which cooperates with an oppositely positioned bore 51 on each latch 48 to receive an expansion spring 52. Springs 52 are suitably arranged in slots 47 to normally bias the latch members 48 radially outwardly to urge the upper ends of members 48 into engagement with the lower face 53 on annular member 54 carried within the central bore of mandrel 26.

As best seen in FIGURES 4 and 5, each of the -members 48 is pivotally supported in its respective slot 47 by a transverse pin 55 lsecured to opposite sides of the slot 47 and received within a lateral passage 56 through each member 48. In this connection, note well, that the lateral passages 56 are somewhat oblong in cross-section so that pins 55 are loosely received therein. Note also that the downwardly facing lateral shoulders 57 and 58 of members 48 are arranged to abut opposed, upwardly facing, shoulders 59 and 60 in slots 47. By this arrangement, longitudinal forces transmitted through members 48 between mandrel 26 and sleeve 34 are not imposed on pins 55. Thus, the pins 55 are protected from damage or deformation by such transmitted forces.

As will be readily seen from FIGURES 2 yand 5, when members 48 are in their latched position, a downwardly directed force on mandrel 26 will be transmitted by downwardly directed faces 53 of annular member 54 to upper end surface 61 of latches 48 and through latches 48 to downwardly directed lateral shoulders 57 and 58 thereof. In turn, lateral shoulders 57 and 58 of members 48 will transmit the force to sleeve 34 through upwardly directed shoulders 59 and 60 thereof. Accordingly, as shown in dotted line (which is somewhat exaggerated to facilitate understanding) in FIGURE 5, this force will not be imposed on pins S5 since they are spatially arranged from the end walls 62 and 63 of passages 56. Similarly, an upwardly directed force on valve assembly 27 will be transmitted through the latch members 48 to mandrel 26 without being imposed upon pins 55.

For releasing the valve assembly 27, longitudinally extending splines 64 are provided within the internal bore of the tubular sleeve 34 and are received in substantially longer complementary spline grooves 65 formed in the periphery of a tubular jack-screw member 66. Internal threads 67 at the lower end of jack-screw member 66 are threadedly engaged with external threads 68 at the upper end of the central tubular member 30. A release sleeve 69 is 4slidably mounted in the uppermost end portion of the jack-screw member 66 and has an enlarged upper end providing an upwardly diverging tapered surface 71. A spring 72 normally biases the release sleeve 69 upwardly to normally maintain the tapered surface 71 a slight distance above downwardly projecting ends 73 of latch members 48.

Accordingly, as best seen by comparison of FIGURES 2 and 3, when it is desired to release the central valve assembly 27 from its locked position, in one manner of operation the test tool mandrel 26 is appropriately manipulated to bring the lugs of the jaying system (not shown) into a circumferential slot portion (not shown) of the system to permit free rotation of mandrel 26 relative to housing 25. In this position of the mandrel 26 relative to the housing 25, a thrust bearing 74 disposed around the mandrel 26 is engaged with the upper end of the housing 25 to carry the downward thrust as the tubing string 9 is rotated. As the mandrel 26 is rotated, the torque is transmitted through the latch members 48 to rotate tubular sleeve 34. In turn, splines 64 of sleeve 34 will rotate jack-screw member 66.

As seen in FIGURE l, when the test tool 21 is in this operating position (i,e., positioned to rotate jack-screw member 66 as above described) at, spring-biased keys 75 on the lower end of central valve assembly 27 are coengaged within slots 81 in an inwardly projecting shoulder 82 on housing 25. In this way, the central tubular member 30 is secured against rotation relative to either housing 25 or mandrel 26. Thus, as jack-screw member 66 -is rotated, the internal threads 67 at the lower end of the jack-screw will be threaded downwardly over external threads 68 of central tubular member 30. Such downward travel of jack-screw 66 will move release sleeve 69 downwardly to bring tapered surface 71 thereof into engagement with the inner face of the lower ends 73 of latch members 48.

It will be appreciated that as tapered surface 71 moves downwardly over ends 73, latch members 48 will be pivoted to shift the upper ends of the members radially inwardly for withdrawing them from engagement with face 53 of annular member 54 ultimately disengaging them from mandrel 26. Once the latch members 48 have been retracted the central valve assembly 27 is freed from the mandrel 26, and may be transported to the surface in any of the above-described manners.

Alternatively, by running a stinger (not shown) into sleeve 34, release sleeve 69 may be simply depressed against the restraint of spr-ing 72 to withdraw members 48 from their latched position by camming their lower ends 73 outwardly.

The normal position for jack-screw member 66 is that shown in FIGURE 2. Thus, when the central valve assembly 27 is inserted into test tool mandrel 26, either at the surface or down-hole, the side walls of the mandrel 26 and/or the tubing string 9 will hold latch members 48 in their retracted position. However, when the central valve assembly 27 is brought into a position in mandrel 26 where the latch members 48 are just below the face 53 of annular member 54, the force of springs 49 will automatically extend them into engagement with the annular member 54 and, thereby, into locked relationship with mandrel 26, as shown in FIGURE 2.

From the foregoing it will be appreciated that latch members 48 may be suitably sized and arranged to withstand substantial forces, so long as the support means employed allow the members to pivot between locked and unlocked positions and shift axially relative to the support means between oppositely directed faces 53 and 59-60. By this arrangement of the support means, little or no force will be transmitted to the latch support means, e.g., pins 55, regardless of the magnitude of force imposed on the latch members. Thus, by employment of this invention, the support means, Whether it be the pins and slots of this embodiment or some equivalent means, may be rendered immune to forces acting on the latch means which might otherwise deform or damage the support means.

Accordingly, it will be recognized that the present invention has provided new and improved releasable latch means whereby a well tool movable between surface and subsurface locations may be selectively engaged with and disengaged from an associated member at a surface location within a well bore without risking costly malfunction resulting from damage or deformation of the latching mechanism.

While one particular embodiment of the present invention has been shown and described, it is apparent that changes and modifications may be made without departing from the invention in its broader aspects.

What is claimed is:

1. In a well tool, means for releasably locking a member thereof to another member when said members are co-engaged with one another comprising:

first and second oppositely-directed abutments spaced longitudinally apart and on said co-engageable members respectively;

a latch member movable into interposition between said abutments for transmitting forces from one coengageable member to the other when said co-engageable members are co-engaged; and

means connecting said latch member to one of said co-engageable members for lateral movement thereon from a retracted position into an extended position between said abutments and including a transverse pin xed to sa-id one co-engageazle member, and an oblong transverse opening in said latch member receiving said pin, said oblong opening being sized along its lateral axis -in relation to said transverse pin to allow said latch member to cooperate therewith and move laterally between its said positions as well as being sized along its longitudinal axis to allow said latch member to move longitudinally in relation to said one co-engageable member and said transverse pin without the longitudinally-spaced ends of said oblong opening contacting said transverse pin so long as said latch member is in said interposed position.

2. In a Well tool having rst and second telescoping members movable relative to one another, means for releasably coupling said telescoping members in one position relative to one another comprising:

rst and second abutments respectively on said telescoping members, said abutments be-ing opposed and releasably coupling said telescoping members in one posispaced from one another when said telescoping memtion relative to one another comprising:

bers are in said one position; lirst and second abutments respectively on said telea movable latch member having oppositely-directed surscoping members, said abutments being opposed and faces respectively arranged to engage said opposed spaced from one another when said telescoping abutments in an extended position of said latch members are in said one position;

member for carrying loads acting from one abutment a movable latch member having oppositely-directed to the other; and longitudinally-spaced end surfaces respectively means supporting said latch member on one of said arranged to engage said opposed abutments in an telescoping members for pivotal movement and for 10 extended position of said latch member for carrying axial movement so that, when said latch member has moved into said extended position between said abutments and said members are in said one position,

loads imposed on one of said telescoping members through said abutments to the other of said telescoping members;

means supporting said latch member on one of said telescoping members for pivotally lateral movement and for longitudinally movement so that, when said latch member has moved laterally into said extended position between said abutments and said members are in said one position, said supporting means are free of loads being carried by said latch member, said said supporting means are free of loads carried by said latch member. 3. In a well tool having first and second telescoping members movable relative to one another, means for releasably coupling said telescoping members in one position relative to one another comprising:

rst and second abutments respectively on said telescoping members, said abutments being opposed and spaced from one another when said telescoping members are in said one position;

supporting means including an oblong transverse passageway through said latch member between said end surfaces with the greater dimension thereof being substantially along the axis of said latch member, and a transverse support member in said passageway and supported from said one telescoping member.

5. The well tool of claim 4 further including:

means operative from the surface for retracting said latch member to release said telescoping members for movement relative to one another.

a movable latch member having oppositely-directed surfaces respectively arranged to engage said opposed abutments in an extended position of said latch member for transferring loads imposed on said telescoping members from,one of said abutments to the other of said abutments; and

means supporting said latch member on one of said telescoping members fou pivotal movement as well as linear movement between said abutments so that, when said latch member has moved into said extended position to position said oppositely-directed References Cited UNITED STATES PATENTS 2,726,848 12/ 1955 Montgomery et al. 285-320 X surfaces between said abutments and said members 2,885,007 5 /1959 Hoger 285 39 X are in said one position, said supporting means are 3,049,367 8/1962 Lashta 285 317 X free 0f loads being transferred by Said latCh mem- 3,127,943 4/1964 Mari 285 322 X ber, said supporting vmeans including an oblong trans- 3,134,513 5 /1964 Regan 2g5 317 X verse opening in said latch member with the greater 2,067,329 11 /1947 McGun 285 g7 dimension thereof being substantially in the direction of said linear movement of said latch member, and

a transverse support member in said opening and supported from said one telescoping member.

4. In a well tool having first and second telescoping members movable relative to one another, means for 285-316, 330, 39

CARL W. TOMLIN, Primary Examiner.

D. W. AROLA, Assistant Examiner.

U.S. Cl. X.R. 

